Another person has died from mosquito-borne encephalitis, and four more cases were confirmed yesterday – bringing the number of definite cases to nine, officials said.

One of the new confirmed cases was an 80-year-old man who lives in Sunset Park, Brooklyn – the first case from that borough.

Officials cautioned that they are still investigating the possibility that the man caught encephalitis away from his home.

Another 80-year-old man, who became the third New Yorker to die from St. Louis encephalitis, lived in the 4-square-mile area of Queens where the first cases were confirmed Sept. 3, Health Commissioner Neal Cohen said.

The other three newly confirmed cases are all from Queens:

*A 78-year-old woman from Whitestone, a neighborhood in the originally designated area.

*A 72-year-old woman from nearby Douglaston.

*A 75-year-old man from Hillcrest, well south of the disease epicenter.

Officials are now investigating 48 other possible cases – but were able to decide that 12 other possible cases were not encephalitis.

City workers using hand-held sprayers were hitting areas near public schools in Queens to protect children, who, along with the elderly, are most susceptible to the worst effects of encephalitis.

Several Queens parks and cemeteries were hit in the latest helicopter spraying blitz.

Officials defended waiting until Sept. 3 to begin spraying, even though doctors at Flushing Hospital had informed the city about suspected encephalitis cases on Aug. 23.

Dr. Marci Layton of the city Department of Health said early test results came back negative.